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Structure and Function of the Human Body: A Broken Heart


Hemoglobin plays an important role for erythrocyte function as it transports oxygen in erythrocytes. Moreover, hemoglobin has direct relation to anemia, a disorder of the blood when the number of erythrocytes decreases. As hemoglobin carries oxygen from lungs to tissues of the body, low level of hemoglobin can lead to lack of oxygen in human organs. Iron is important in erythrocyte function because iron helps to bind oxygen. (Anthea et al., 1993, p.21)


The flow of blood through the body is a complex process. When the heart expands and contracts, the blood is pumped through the veins; then the arteries transport the blood back to the heart. Capillaries join the veins and the arteries. The heart is a four chambered organ which has two atria- left atrium and right atrium, and two ventricles – left ventricle and right ventricle. Their function is to contract and relax in order to pump blood. Pulmonary circuit is when the blood flows from the right ventricle to the lungs through pulmonary artery and back to the left atrium through the pulmonary vein. During this process, carbon dioxide exchanged to oxygen. Systemic circuit is when oxygenated blood flows from the left ventricle to the tissues of the body and venous blood is returned to the right atrium. (Kirby, 2007, p.28)


There are many different factors that affect blood flow. Among them are the increase in blood viscosity, obstruction in blood vessels, the presence of chemical substances that change blood flow and so on. For example, diabetes can be considered as one of the factors that affect blood flow. The increase in glucose makes the blood thicker and it decreases the flow. The other example is when blood flow is changed due to blockage in the blood vessels. Atherosclerosis is a disease when plaques appear on the walls of the blood vessels and reduce the pathway. (Manalo, 2010, para.2)


Cardiac conduction system consists of several cardiac muscle cells located in the walls of the heart which are used to send signals to the heart muscle in order to cause its contraction. The major components include the SA node, AV node, Purkinye fibers, bundle brunches. Electrocardiogram is used to identify tachycardia, when there is an increase in the frequency of heart contractions, bradycardia, when heart beats less than 60 times per minute, cardiac arrhythmias, when the heart beats too fast and too slow, or irregular. Ectopic pacemaker is located in the right atrial wall in the upper part of the heart. This heart area can cause abnormal cardiac rhythm. (Kirby, 2007, p.22)


The function of arteries is to transport oxygenated blood from the heart to all other parts of the body. In other words, arteries help the heart to pump blood throughout the body. (Bingaman, 2010, para.2)The vein’s function is to transport deoxygenated blood back to the heart. Capillaries are necessary to join the blood flow from arteries to veins in the human body. In capillaries the exchange of gasses and nutrients takes place. (Anthea et al., 1993, p.32)



Anthea, M., Hopkins, J., McLaughlin, C., Johnson, S. Warner, M., LaHart, D., Wright, J. (1993). Human Biology and Health. Prentice Hall
Bingaman, M. (2010) What are the Functions of Artery? Ehow.com. Retrieved from:<http://www.ehow.com/facts_5813488_functions-artery_.html>
Kirby, M. (2007) Cardiac Development. Oxford University Press.
Manalo, P. (2010) Factors that Affect Blood Flow. Hel’um. November 2, 2010. Retrieved from:<http://www.helium.com/items/2000365-blood-flow>